Widens the #160 fix, which was scoped too narrowly to host role, and fixes
flare-edge#168.
Device role was deliberately left alone on the reasoning that the state
machine is only meaningless when the port is a host. That was wrong. On a
board with no extcon phandle the machine has no external role signal in
EITHER direction, and with bvalid pinned high by the VBUS bypass its charger
detection cannot be meaningful at all. In device role its verdict suspends
the phy underneath a bound gadget, so the USB recovery link dies.
Reproduced deterministically on warden-c8a3 with a host attached:
device role, host attached ccf=1 phy_sus=0x0 udc=configured works
-> host role ccf=1 phy_sus=0x0 udc=(none)
-> back to gadget ccf=0 phy_sus=0x1d1 udc=configured SUSPENDED
-> +15s / +30s ccf=0 phy_sus=0x1d1 udc=configured never recovers
and the 2207:0019 device disappears from the host for good.
Nothing notices, because every obvious signal lies: udc state reads
"configured", usb0 carrier reads 1, and DCTL RUN_STOP reads 1, so the gadget
really is asserting its pullup. It asserts into a phy whose analog front end
and 480M clock are off, so the SoC sees SE0 and the host sees no device at
all, not even an enumeration error.
It cannot self-heal either. bvalid is pinned high, so a host attaching later
produces no VBUS edge for the machine to trigger on: it ran once, powered the
phy off, and nothing re-evaluates. That is why a reboot appears to fix it and
why this read as a cable fault for weeks. It is not, and the cables were fine.
Gated on the extcon being self-allocated rather than on the board compatible,
so it describes the actual precondition: no external role signal exists.
Renamed from 29-usb2phy-no-otg-sm-in-host.patch, whose name now misstated the
scope.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MVGTC78dgCGfRANNKjoPea
